docs: rate limits table with search

[unatasha8]

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Further comments

[jhickmanit]

I think I will echo what Patrik put into the code PR for this. I am not sure if customers will understand or care about the cost bit. When they simply see something like kratos-public-low they will think it is requests that have a low ratelimit ceiling rather than low cost. I hate to derail this, but we might want to think about how to better label this for the public.

[jhickmanit]

Should we split the technical below into another document? It feels odd to get into the "how" when we are explaining the why above.